masera



C. MASERA.

ELECTRIC FURNACE.

APPLICATION FILED no.9, ma.

Patented Nov 4, 1919.

6 SHEETS-SHEET l.

C. MASERA.

ELECTRIC FURNACE.

. APPLICATION FILED DEC. 9. 1918. 1,320,884. Patented Nov. 4,1919.

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C. MASERA.

ELECTRIC FURNACE. APPLICAHON men ntc.s.1 -1a..

Patented Nov. 4, 1919.

6 SHEETS-SHEET 3.

C. MASERA.

ELECTRIC FURNACE.

APPLlCATlON FILED DEC. 9. l9l8.

1,320,884. Patented Nov. 4, 1919.

5 SHEETS-SHEET 4.

"C. MASERA.

ELECTRIC FURNACE.

APPLICATION FILED was. 1918.

I Patented Nov. 4, 1919.

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C. MASERA.

ELECTRIC FURNACE.

APPLICAJ'IQN FILED 020.9.1918.

1 20,884, 7 Patented Nov. 4, 1919.

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angle irons, covering the CARLO MASERA, or TURIN, ITALY.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Nov. 4., 1919.

Application filed December 9, 1918. Serial No. 265,932.

To all whom it may concern:

Be it known that I, CARLO MASERA, a subject of the King of Italy, residing at and whose postal address is 11 Via Principi dAcaja, Turin, in the Kingdom of Italy,

have invented certain new and useful Improvements in Electric Furnaces; and I do hereby declare the following to be a full,-

clear, and exactdescription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accomr panying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

This invention has for its object some' new and useful improvements in the electric furnaces for melting and refining steel and metallic alloys, by which the efficiency and duration of the furnace are increased and a cooling of the electrodes is effected while at the same time said electrodes are protected from the outside air as well as from the circulation around them of the gases produced in the furnace whereby they are not subject to wear out.

In the annexed drawings are shown, by way of example, two diagrammatical constructional forms of the object of this invention.

Figure 1 is a vertical axial section of the whole of the furnace;

Figs. 2 and 3 are detailed views, in larger scale, of the electrode holders;

Fig. i is a vertical section of a modified constructional form of the furnace;

Figs. 5' and 6 are detailed views of the electrode holders, according to Fig. 4.

' The furnace is constituted by:

(a) A cylindrical metallic sheet casing 1 suitably reinforced and provided with 7 wall of refractory material of the furnace. Said casing is provided on one side with the'inlet 2 and on.

the other side with the pouring spout 3, which is inclined in order to prevent any accidental escape of molten metal when the furnace is horizontal. of said cylindrical casing are secured two cradles 4 in shape of arcs of circles, resting on two flat guides 5, so that the furnace may swing in either direction, when it is necesv sary to pour the molten metal or to carry away the slags or even when it is necessary to stir the molten mass. Said oscillations of the furnace are obtained by means of hywhich jections 20,

To the lower part perfectly draulic action through two oscillating hydraulic cylinders 8, hinged at their base while their rods are hinged to the end of the cradles 4:. By means of a distributing device 9 it is possible to cause the piston to move in either direction in order to ob' tain the rotation of the furnace in the desired direction.

(1)) An iron frame 10 forming the roof ring and resting on the furnace frame.

(a) A circular ring 11 secured by means.

of bolts to four uprights 12 secured in their turn on one side of the furnaceframe and so connected to each other at their upper part as to form a network or frame 12*. To,

said ring 11 'is secured the steel covering 13 on which the three electrode holders are placed.

The whole system constituted by the lateral uprights 12 with upper network, ring or frame 12 and steel armature with its electrode holders is movable in order to allow the removal of the roof during'the working of the furnace.

(03) Three electrode holders, each of them being constituted by a cylinder 14 around water circulates and in which slides the carbon C (Figs. 2 and 3). In said cylinder are secured two rings of insulating material 15, which guide the carbon and prevent any contact between the same and the metallic part of the casing. The cooling cylinder is closed at its upper part by a steel ring 16 provided with a packing of insulating material 30, and sliding with a perfect contact against the bronze jacket 17. This latter is held at its upper part by the steel ring 18, which is connected with the bronze carbon clamping terminal 19, constituted by three sectors so connected together by means of bolts as to hold the carbon, thus securing this latter within a tight casing, consisting of the disk 18 and jacket 17. The disk 18 is provided with two prothrough which it is secured to two nuts 21, fitted on the screws 22. These latter are actuated by means of two worm gears 23 and 24 driven by a motor 25, provided with a brake 26 and driven from a distance by means of an automatic or hand commutator. The rotation of the screws'22 causes therefore the axial displacement of the electrodes and therefore the arc control. Suitably disposed insulating layers insulate the carbon and the terminal clamps from the other metallic parts of the carbon holder while a second packing 19- arranged under the clamp insures a tight closure of the casing. By this'arrangement "the upper part of theelectrode is always free so that continuous electrodes may be used; moreover, from the current inlet until their ending in the furnace, the electrodes are perfectly protected from the outer air and no draft producing an injuring gas circulation is possible around the electrodes.

The energy distribution system on the secondary circuit consists of four wires, three of which in phase lead the current directly to the electrodes while the fourth wire is connected with three special terminal clamps at the bottom and at the furnace hearth and constitutes the center of the system.

The furnace hearth is made conducting of electricity by adding-to the refractory materials suitably chosen conducting substances.

The arcs are formed between the electrotrodes and the furnace hearth or between the electrodes passing through the metal of the charge according to the greater or smaller resistance met by the. current on its flow.

According to a modified form of this invention, shown in Figs. 4, 5,6, the ring 11 and the covering 13 are dispensed with and therefore the electrode holders, instead of being connected with the covering 13, are secured to the upper part of the network or framing 12 by means of the anglebar A. Moreover the cooling cylinder lies directly on the furnace roof, so that a perfect closure between the bottom of the cooling cylinder and the roof is obtained.

However,'as the roof under the heat effect, expands and is lifted up, in order to prevent the coolin cylinders from becoming inclined, a ring Bis arranged'on the covering of each electrode holder, in said ring i cylinder 14: is guided and forced to raise in the direction of its axis even when the deformation of-,. t he roof takes placedn an irregular ways;

It has also been found convenient to arrange the cooling water inlet and outlet ta s '-a ring carrying said clamp and having nuts thereon, screws on which said nuts are arranged to travel, means for actuating said screws simultaneously to raise and lower said electrode and cylinder, a cooling jacket at the furnace roof for said electrode telescop ing with said cylinder and a packing between said jacket and cylinder.

2. In an electric furnace, removable metallic roof covering, a rin supporting the same, uprights detachably secured to the sides of the furnace and connected to said ring, a frameworkconnecting the said uprights above said ring, electrode holders supported by said covering, and means for raising and lowering said electrode holders supported by said framework.

3. In an electric furnace, uprights attached to the furnace, a framework above the furnace connecting and supported by the uprights, angle bars secured to said framework, electrode terminal clamps su ported by said angle bars, guiding means or said electrode holders, a cooler for an electrode mounted in said guiding means, and a cover for the electrode in telescoping relation to the cooler, said cooler resting on the furnace roof and guided by said guiding means during deformation of the roof by heat.

4. In an electric furnace, a cooling jackci. apacking at the upper and lower portions P the jacket through which an electrode slides, a terminal clamp for the electrode and a cylinder connected to said clamp in packed telescoping relation to the cooler, whereby an electrode holder in said clamp will be freed from circulation of gases along it under all conditions of operation; a

In testimony that 1 claim the foregoing as my invention, 1 have signed my name.

CARLO MASERA. 

